const formatTime = date => {
  const year = date.getFullYear()
  const month = date.getMonth() + 1
  const day = date.getDate()
  const hour = date.getHours()
  const minute = date.getMinutes()
  const second = date.getSeconds()

  return `${[year, month, day].map(formatNumber).join('/')} ${[hour, minute, second].map(formatNumber).join(':')}`
}

const formatNumber = n => {
  n = n.toString()
  return n[1] ? n : `0${n}`
}

const getLunarDay = (needYear, date = new Date) => { // needYear 是否显示年份
  //定义全局变量
  var CalendarData = [];
  var madd = [];
  var tgString = "甲乙丙丁戊己庚辛壬癸";
  var dzString = "子丑寅卯辰巳午未申酉戌亥";
  var numString = "一二三四五六七八九十";
  var monString = "正二三四五六七八九十冬腊";
  var weekString = "日一二三四五六";
  var sx = "鼠牛虎兔龙蛇马羊猴鸡狗猪";
  var cYear, cMonth, cDay, TheDate;
  CalendarData = [0xA4B, 0x5164B, 0x6A5, 0x6D4, 0x415B5, 0x2B6, 0x957, 0x2092F, 0x497, 0x60C96, 0xD4A, 0xEA5, 0x50DA9, 0x5AD, 0x2B6, 0x3126E, 0x92E, 0x7192D, 0xC95, 0xD4A, 0x61B4A, 0xB55, 0x56A, 0x4155B, 0x25D, 0x92D, 0x2192B, 0xA95, 0x71695, 0x6CA, 0xB55, 0x50AB5, 0x4DA, 0xA5B, 0x30A57, 0x52B, 0x8152A, 0xE95, 0x6AA, 0x615AA, 0xAB5, 0x4B6, 0x414AE, 0xA57, 0x526, 0x31D26, 0xD95, 0x70B55, 0x56A, 0x96D, 0x5095D, 0x4AD, 0xA4D, 0x41A4D, 0xD25, 0x81AA5, 0xB54, 0xB6A, 0x612DA, 0x95B, 0x49B, 0x41497, 0xA4B, 0xA164B, 0x6A5, 0x6D4, 0x615B4, 0xAB6, 0x957, 0x5092F, 0x497, 0x64B, 0x30D4A, 0xEA5, 0x80D65, 0x5AC, 0xAB6, 0x5126D, 0x92E, 0xC96, 0x41A95, 0xD4A, 0xDA5, 0x20B55, 0x56A, 0x7155B, 0x25D, 0x92D, 0x5192B, 0xA95, 0xB4A, 0x416AA, 0xAD5, 0x90AB5, 0x4BA, 0xA5B, 0x60A57, 0x52B, 0xA93, 0x40E95];
  madd[0] = 0;
  madd[1] = 31;
  madd[2] = 59;
  madd[3] = 90;
  madd[4] = 120;
  madd[5] = 151;
  madd[6] = 181;
  madd[7] = 212;
  madd[8] = 243;
  madd[9] = 273;
  madd[10] = 304;
  madd[11] = 334;

  const handledTime = handleCurrentDate()
  if (handledTime.yy < 1921) {
    return ""
  } else {
    handledTime.mm = (parseInt(handledTime.mm) > 0) ? (handledTime.mm - 1) : 11;
    e2c(handledTime.yy, handledTime.mm, handledTime.dd);
    return GetcDateString();
  }
  function GetBit(m, n) {
    return (m >> n) & 1;
  }

  // 处理当前时间戳
  function handleCurrentDate() {
    const D = new Date(date)
    let yy = D.getFullYear();
    const mm = D.getMonth() + 1;
    const dd = D.getDate();
    const ww = D.getDay();
    const ss = parseInt(D.getTime() / 1000);
    if (yy < 100) yy = "19" + yy;
    return {
      yy,
      mm,
      dd
    }
  }

  //农历转换
  function e2c() {
    TheDate = (arguments.length != 3) ? new Date() : new Date(arguments[0], arguments[1], arguments[2]);
    var total, m, n, k;
    var isEnd = false;
    var tmp = TheDate.getYear();
    if (tmp < 1900) {
      tmp += 1900;
    }
    total = (tmp - 1921) * 365 + Math.floor((tmp - 1921) / 4) + madd[TheDate.getMonth()] + TheDate.getDate() - 38;

    if (TheDate.getYear() % 4 == 0 && TheDate.getMonth() > 1) {
      total++;
    }
    for (m = 0; ; m++) {
      k = (CalendarData[m] < 0xfff) ? 11 : 12;
      for (n = k; n >= 0; n--) {
        if (total <= 29 + GetBit(CalendarData[m], n)) {
          isEnd = true; break;
        }
        total = total - 29 - GetBit(CalendarData[m], n);
      }
      if (isEnd) break;
    }
    cYear = 1921 + m;
    cMonth = k - n + 1;
    cDay = total;
    if (k == 12) {
      if (cMonth == Math.floor(CalendarData[m] / 0x10000) + 1) {
        cMonth = 1 - cMonth;
      }
      if (cMonth > Math.floor(CalendarData[m] / 0x10000) + 1) {
        cMonth--;
      }
    }
  }

  function GetcDateString() {
    var tmp = "";
    if (needYear) {
      /*显示农历年：（ 如：甲午(马)年 ）*/
      tmp += tgString.charAt((cYear - 4) % 10);
      tmp += dzString.charAt((cYear - 4) % 12);
      tmp += "(";
      tmp += sx.charAt((cYear - 4) % 12);
      tmp += ")年 ";
    }
    if (cMonth < 1) {
      tmp += "(闰)";
      tmp += monString.charAt(-cMonth - 1);
    } else {
      tmp += monString.charAt(cMonth - 1);
    }
    tmp += "月";
    tmp += (cDay < 11) ? "初" : ((cDay < 20) ? "十" : ((cDay < 30) ? "廿" : "三十"));
    if (cDay % 10 != 0 || cDay == 10) {
      tmp += numString.charAt((cDay - 1) % 10);
    }
    return tmp;
  }
}

/**
 * 将小程序的API封装成支持Promise的API
 * @params fn {Function} 小程序原始API，如wx.login
 */
const wxPromisify = (fn) => {
  return function (obj = {}) {
    return new Promise((resolve, reject) => {
      obj.success = function (res) {
        resolve(res)
      };

      obj.fail = function (res) {
        reject(res)
      };

      fn(obj)
    })
  }
};

function throttle(fn, gapTime) {
  if (gapTime == null || gapTime == undefined) {
    gapTime = 16
  }
 
  let _lastTime = null
 
  // 返回新的函数
  return function (e) {
    // console.log(this)
    let _nowTime = + new Date()
    if (_nowTime - _lastTime > gapTime || !_lastTime) {
      // fn.apply(this, arguments)   //将this和参数传给原函数
      fn(this,e)    //上方法不可行的解决办法 改变this和e
      _lastTime = _nowTime
    }
  }
}

module.exports = {
  formatTime,
  getLunarDay,
  wxPromisify,
  throttle
}
